I used to breed tricolor mice when I was a teen. They were so cute! I started with a sweet petable male who was tan and white, then got him a girlfriend who was black and white. All of the babies were black and tan and white, some with the cutest spotty patchy faces!
But it did get rather out of control. A neighbor wanted to feed them to his snake, I was not having that! Eventually my mom decided she was not buying any more tanks and she was tired of the collection I already had... it took months to find homes for them all.
But I don't like rats. They took over the chicken area at our previous place. They even ate a 3 month old pullet by squeezing through a tiny gap!